1. Field of the Invention
The present invention relates to the field of vehicle maintenance, and more specifically, to servicing automatic transmission and power steering fluid subsystems.
2. Background
Each of the numerous fluid subsystems in conventional automobiles require frequent servicing by exchanging used up or broken down fluid with fresh fluid to maintain such subsystems and thus the vehicle in top working condition and extend the life of the subsystem components and associated vehicle. In servicing these subsystems, such as the transmission fluid, engine oil, power steering fluid, engine cooling, and hydraulic fluid, it is often desirable to replace the corresponding fluids in each of these components at the same time either in accordance with a preferred maintenance plan, out of convenience, or of necessity. Two of the more common fluids requiring replacement at the same time are the automatic transmission fluid and the power steering fluid.
Initial attempts at fluid servicing devices were dedicated to exchanging fluid with a particular fluid subsystem. For instance, examples of power steering fluid exchangers may be found in U.S. Pat. No. 5,415,247 to Knorr and U.S. Pat. No. 6,035,902 to Dixon. As pointed out in the Dixon patent, an operator using of the Knorr device may damage the power steering pump due to the placement of the hose ends in the power steering fluid reservoir. Moreover, as the Dixon patent points out, it is preferable to turn the steering wheel of the vehicle during the power steering fluid exchange procedure due to delivering fresh power steering fluid into the upper portion of the fluid reservoir and withdrawing used fluid from a lower part of the fluid reservoir. However, the devices described in these patents do not appear to allow the operator such remote control facilitating the wheel turning procedure while maintaining command of the pumps. In addition both the devices in the Knorr and Dixon patents include open ended hoses to place in the power steering fluid. Thus, when the pumps are deactivated and the hoses are removed from the power steering reservoirs, the remaining fluid in the hoses often spilled adding to undesirable clean up time.
While the Knorr patent indicates that other fluid subsystems may be serviced, the use of such devices for say, servicing an automatic transmission would be unsatisfactory due to the lack of flow control features. For example, attempts to use the Knorr device to service the transmission fluid compartment would run the risk of damaging the transmission pump as well. Thus, it is unlikely that these devices would be used for other than servicing power steering fluid reservoirs and that additional fluid servicing machines would be necessary to carry out the servicing procedures of other fluid reservoirs in the vehicle.
Thus, while many of these devices have proven satisfactory in their performance for servicing a particular fluid reservoir, multiple machines are typically required to service more than one fluid subsystem thus adding time as the service technician had to couple and decouple multiple machines in order to service more than one subsystem. As multiple units were required, the service room floor required more storage space for the machines when not in use.
One such device attempting to alleviate this problem can be found in U.S. Pat. Nos. 5,806,629 and 5,853,068, both to Dixon et al. However, such device incorporates an overly complex motor pump unit and associated plumbing components adding to the overall expense of the machine.
While many of these devices have proven satisfactory in their performance there remains a push for reducing the number of components, cost of manufacture, and reduced assembly time while maintaining the capability to perform the desired procedures. What is needed is a fluid changing apparatus configured to conveniently address the needs of the fluid change operator in servicing the various fluid reservoirs in an automobile using an integrated fluid servicing apparatus having a relatively minimal component fluid transfer system, something the previous attempts have failed to achieve up to this time.